[Ian Stuart Forsyth]

chicken.

One of the rules I use is that objects that fall outside the DOF are always more blurry than the diffraction introduced to put that object into the DOF.

[Mattox]

Going smaller than f/11 is going to take away peak sharpness with K-1. Going smaller than f/16 starts to look like catastrophe. High IQ lens loses its advantage right there.

No rocket science needed. F/8 is "safe" and f5.6 ~optimal with K-1.

True but not the case in landscape photography if you aren't focus stacking

[Digitalis]

Going smaller than f/11 is going to take away peak sharpness with K-1. Going smaller than f/16 starts to look like catastrophe. High IQ lens loses its advantage right there.

The funny thing is that both good and bad lenses look exactly the same at f/29. The important thing to remember is that diffraction is a gradual effect, images do not suddenly turn to custard after f/11: Diffraction is already in effect past f/5.6 with a majority of lenses*. So many people who think they are worried of losing detail if they stop down more than f/11 are deluding themselves. Sometimes it is better to get the whole shot in focus in one hit, rather than trying to mince out every last Lpp/mm out of a lens. Focus stacking can be a pain, and cannot be used with rapidly moving subjects. T/S lenses have optical shortcomings the the extremities of their image circle...there are always compromises involved. Regarding diffraction there are sharpening techniques that can be used to recover acutance that is reduced by the effects diffraction. Sure, not all detail can be recovered but it is better than nothing.

i'm just going to leave this here:

Pentax K5IIs - Sigma 8-16mm f/4.5-5.6 @ 16mm - Left f/29, Right f/5.6 -100% crops

*though lenses often have aberrations that are significant enough to mask it, so it only becomes visually detectable past f/8.

[interested_observer]

how do you magnify with the K1 for focus. It is so completely different to the K5

Hit OK in LV

You have to be in Live view and then you hit Ok button. The amount of magnification can then be chosen using an e-dial, or as an option somewhere in the Menu (I think its called Digital zoom). The good thing about this digital zoom is that it opens the aperture of the lens, so you can do some precise focusing. This is especially great with very fast primes and with manual focus, because Live view alone usually stops down the lens a little. And you can use this in combination with focus peaking.

Thanks!!! Been reading the manual and playing with the camera - in the dark and this nugget of information has eluded me. Using this for star focusing for astrolandscapes. I'm finding - especially here in the winter, that I can't just pre-focus during the day and taping the focus ring on the lens down, for shooting at night. With the cold temperatures, I need to spend the 10 to 30 minutes getting in focus out in the field (dark, cold, tired, etc.).

[Kerrowdown]

believe that would be 1/3 the way into the scene. If you look at a DOF scale on an old-school lens, you'll see you get more distance in focus beyond what you focused at than in front for a given aperture.

Aye +1, this is my MO too.

[sibyrnes]

Going smaller than f/11 is going to take away peak sharpness with K-1. Going smaller than f/16 starts to look like catastrophe. High IQ lens loses its advantage right there.

No rocket science needed. F/8 is "safe" and f5.6 ~optimal with K-1.

According to the results of lens resolution tests posted at http://www.takinami.com/yoshihiko/photo/lens_test/index.html, many Pentax primes achieve max resolution at f11. Some, like the famous K 28mm f2 for example, achieve better resolution at f 16 than at f5.6.

[Wheatfield]

FOCUS METHOD IN LANDSCAPE PHOTOGRAPHY

As mentioned interestingly enough in a previous post not related, what are you finding to be the most accurate and effective focus technique for shooting landscape/still photography with the K1?

Manual focus works best for me in these situations.

[JensE]

Then there is a big but. Low MP bodies work reasonably fine using the hyperfocal concept. But when you do large print of a picture taken with something like K-1 (and higher res) the outcome will look messy due to nothing really being sharp (unless something hits the real focus point) or diffraction softening with small aperture.

Real solution is to use tilt effectively or focus stacking. That is the only way as MP count just seems to rise for no real reason.

For pictures which extend to the horizon, I don't think that the hyperfocal concept is dead in any way for 36MP. Depending on the subject, it can even work at 28mm. I almost always focus my two very wide primes (Color Skopar 20mm on K-1, DA 15mm on K-5) by DoF marks, stopping down two stops further though.

The sensor pitch of the K-1 is about 0.005mm, or 0.008mm diagonally. A circle of confusion about twice the linear pitch (d=0.01mm) is used for a 36MP image by Schärfentieferechner mit Zusatzfunktionen, a reliable and thoroughly discussed and checked calculator. Traditional lens DoF marks usually assume a circle of ~0.03mm, e.g. the Pentax F 28mm does, the HD DA 15mm uses 0.2mm. You'll see that for f=28mm, only at f/14.6 diffraction gets as big (by 50% falloff) as the geometric 0.01mm circle of confusion. "Optimal" aperture is at f/9.7, i.e. the aperture at which diffraction starts to theoretically outweigh the increase in sharpness when stopping down further. In practice, I start to see a very subtle difference under careful examination at f/16 for pictures without pixel shift. Choosing something around f=11 would give you greatest depth of field, which still appears critically sharp, resulting in a hyperfocal distance of 10.4m, or a range from 5.2m to infinity. It translates to a human observer looking at e.g. a 65cm wide print from 30cm distance (=naked eye of a pixel peeper) perceiving it as sharp within the limits of human eyesight.

For me in practice, for 20mm it is 3m to infinity at f/11, and most of the time I go slightly into the diffraction-limited range with f/16 to give the corners a little extra boost for overall best performance.